What is the quickest way to make all the cells in defined range have the
number format (NumberFormat = "0") when
they show the hash sign due to an incompatible value with the date format?
These cells have values such as 18950315, which is an Interbase integer date
format.
After the format is changed to number these values will have to be converted
to a string showing the date.
All these values are pre Excel dates, but the problem is that they are
intermixed with normal Excel compatible dates
that are handled in a different way.

I have code that does the job, but it is slightly slow:

Sub ChangeHashesToDates(ByRef rng As Range, Optional ByVal strFormat As
String = "")

Dim c As Range

Application.StatusBar = _
" Converting pre Excel dates, please wait ..."

If strFormat = "" Then
For Each c In rng
If Len(c.Text) = 32 Then
c.NumberFormat = "0"
c.Text = Right(c.Value, 2) & "/" & _
Mid(c.Value, 5, 2) & "/" & _
Left(c.Value, 4)
End If
Next
Else
For Each c In rng
If Len(c.Text) = 32 Then
c.NumberFormat = "0"
c = Format(DateSerial(Left(c, 4), _
Mid(c, 5, 2), _
Right(c, 2)), _
strFormat)
End If
Next
End If

End Sub


Thanks for any advice.